Oscillating belt sander



1,628,531 May 10, 1927' G, H. C'ARLSON OSCILLATI NG BELT SANDER FiledMarch 26, 1924 3 Sheets-Sheet 1 May 10, 1927.

' 1,628,531 G. H. CARLSON QSCILLATI NG BELT SANDER Filed March 26, 1924 3 Sheets-Sheet 2 May 10 1927.

7 1,628,531 G. H. CARLSQN OSCILLATING BELT SANDER Filed March 26, 1924 a Sheets-Sheet3 Patented May 10, 1927.

maven srarss ram FFICE.

GEORGE H. CARLSON, or e'ooxronn; rLLIrioIs, ssier'ron TO REDIN, nxsrnoma COM- }?A1\TY, 0F ROCKFORD, rumors, A ooaronarroii or ILLINOIS.

OSCILLATIN G BELT SANDER.

Application filed March 26, 1924. Serial No. 701,929. 1

This invention relates to the art of abrading and has more particular reference to machines employing a traveling endless flexible band or belt of abrading material to which is imparted a bodily transverse reciprocation. In these machines the work-piece is supported on a suitable table or carrier and brought into contact with the periphery of the traveling-band so as to be surfaced by an abrading action, the purpose of the re ciprocating or oscillating movement of the traveling-band being to prevent streaks or grain marks in the finished surface of the work. The present invention pertains especially to machines of this type in which the traveling-band has a sand abrasive, or the like, adapted for surfacing flat curved or shaped wood pieces,- these machines being known in the trade as oscillating belt sanders. I

The primary purpose of the present invention is to improve the construction and operation of sanders of'thecharacter described, with the view to reducing friction losses and lowering power consumption, and to provideja machine which is thoroughly practical, long-lived, and capable of production at a comparatively low cost.

In furtherance of the foregoing I have provided improved means for supporting and reciprocating the traveling-band, consisting preferably, but not necessarily, in a lever mechanism of novel construction, which supports and operates a bed or carrier for the traveling-band, and in providing springs serving to counter-balance the weight of the bed and parts carried thereby, the arrangement being such that there is but little friction resulting from the reciproeating action and but little power is required for transmitting such action.

I have also aimed to provide an improved table support for holding the work-pieces at any desired angle with respect to the traveling band.

Other objects and attendant advantages will be appreciated by those skilled in this art as the invention becomes better understood by reference to the following description when considered in connection with the accompanying drawings, in which Figure 1 is a side elevation of a sander ant: i

part in section being taken on the line 22 of Fig. 1;

Fig. 3 is a horizontal section taken substantially on the line 33 ofFig. 1;

Fig. 4: is a detail section taken on the line t4 of Fig. 2;

Fig. 5 is a vertical transverse section taken on the line 5-5 of Fig. 1; V i

Fig. 6 is a. fragmentary section takenstantially-on the line 66 of Fig. 2; H

Figs. 7 and 8 are detail sections taken on the lines 77 and 88, respectively, of Fig. 3;

Fig. 9 is a detail section taken on the line 99 of. Fig. 6; and

Fig. 10 is a detail section taken on the line 1010 of Fig. 1.

In this machine the abrading element is in the form of an endless flexible belt 11 the peripheral face of which is coated with a sand abrasive or any suitable abrading material. This abrading element, hereinafter referred to as the traveling-band, is trained over a driving roll 12 and an idler roll 13 suitably journaled on vertical. axes on a bed designated generally by 14. The bed in turn is mountedthrough the intermediary of a lever mechanism (described hereinafter) upon a base designated generally by 15. Suitable means may be employed for rotating the driving roll for imparting rotation to the traveling-band; and said lever mechanism will .be operated by suitable means for vertically reciprocating the bed 14: and consequently the traveling-band. The workpieces to be surface-d maybe brought into and out of contact with the sander face of thetraveling-band while supported on either or both of the tables 16 and 17, which likewise will be described more particularly hereinafter.

The means at present employed for rotating the driving roll comprise a drive shaft 18to which the driving roll is-fixed, this shaft being journaled in an'upper bearing 19 mounted on the top of the bed 14 and a lower bearing 21 carried by an underhanging bracket 22 also fixed to said bed. Said shaft may be driven by any suitable means such, for example, as a belt pulley 23 driven from any suitable source.

The idler 1601113 is suitably journaledin ed b iii'g bracket designated i139 supperted subclining or tilting); the idler roll t l inn a pair oi opposed hand-adjuat'able screw utopa Ell l between the ad acein ends: of which in interponed the lower end t-lo l :1 depending: arm 5' i integral with the hearing brarliet Ell. "he ecrew irtops i l-l clamp the end ill: and hold the bearing; ln'ncltet ff-l and coneeipiently the idler roll 13 in a Pet position with reapect to the vertical. lily eijliuetnientoi eaid screw stops it will be nianite'at that the bracket ill may be tilted on the pivot pin tor in" i in one direction or the other for changing the poeition ot the traveling-hand thercoi'i. in; well known in this art. The lever nieel'iauiani above referred to which supports: the bed l-.!-. and t 'ansinits recipr catory i'noveinent thereto coinprisee in the preferred einbi'uliinent, a pair of levers 37 and 38 of the first class. These lovers are preferably in the form of comparatively heavy castings, each having; a truiinion type :lulcrnin on the base. the distance between the trunnion bearings for each lever being sutfieient to give a stable eupport tor the bed and other parts "arried thereby and the cast:- ings being oi": sntlicient size to amply carry the weight of such parts. Viewing Fig. 3 it will be seen that the fulcrum portion 39 and the \veighhcarrying portion ll of each lever are uniform in Width and that the force-applying); end oi the lever 37 biturrated to receive the torce-applyino end of the lever 38. The i'ulcrum For each lever is established by a pivot pin :tEl passed through each :l'ulcruni portion 32') and nrovidinn trunnion ends journaled in suitable. bearing); blocks {l3 lined to the top oil: the basic. t pivot pin lt passed through the end all oi the lever ill" in journaled at its ends: in l ')0tlling blocks 3 bolted to the under eide oi the bed 1%, th n establiehina a pivotal connection therewith. The end "ll. of the lever fiti is likewise pivotally ci'innertod to the bed ll by means ot a pivot pin journaled in bearing" blocks t-i bolted to said bed, but in this instance said end etl of the lever 38 has a sliding connection with the pin 41:6. Viewing Fig. 8 it: will be seen that the pivot: or connecting pin tit i. shaped to provide flat hearing; 'l'aces t8 which are engaged by coniple mental faces on the lever. For convenience in manufacture the end 4-1 of the lever 38 is separated into two similar arms each of which is slotted lengthwise so that its fiat hearing t'aeea may be relatively adjuijsted liy in ans ol' :1 bolt it) thrriiug h each slotted arm olf said lover its; hearing: lacei: may be drawn t ;,1'ct'lier to serure the proper contact- \vith the lace; {lit and to talte up t'or wear. The tort-mapplying ends ol" said lever. dieponed in juxtapoiiitiou as deeoribed. are pivotully connected by means: ol a pin 51 journaled in the end 5: ol the lever 1th and in earing blocltsi 53;, h ated between hearing l'acea til (Fig. 7) in the alotted end ho oi the. lever 37. The pin til is clamped to the lever end 52 by meana ol a bolt tilt and clamp holtn 2-7 nerve to take up \voar between the. 'lacea hi and the blocks tifl.

From the loi'eegoirur it will be nuiniteet that by moving; the pin til back and forth in a vertical plane. the bedll and part9 carried thereby such tie the band ll and in platen Til will be raieed and lowered in a parallel movement, than ll'lll'litllll'lfl bodily transverse reciprocati n to the traveling} band. In order to talte (are ot the play between the PlYOl'Hlly connected ends of the levers 37 and 38 the slide connection above dcacribed is provided; and inasmuch as the bed is connected by a lived pivot to the lever 37 and the latter is 'lnlerumed in fixed hearings the arcnate travel. of the pivot pin 46 is taken care of by the slide connection aleo described above.

Suitable means may be employed for iniparting vertical reciprocation to the pin 51, such as an eccentric 58 fixed to a drive Shaft:

53. and connected by means of an eccentr ie hand (31, connecting rodtSQ and yoke 63 to the outer ends of said pin as clearly shown in Figs. 1 and The shatt- 59 may be. coir tinuously revolved in either direction by any suitable driving 111M118. At present said shaft is driven from the shaft: 18 above mentioned, tln'onggjh the agency of: an endless belt. ti-ttrained over a pulley (t5 fixed to the shaft 5!), a pulley (it; fixed to the eha'tt l8 and an intermediate idler pulley ($7.

in order to relieve as much Weight as possible from the bearings ol the .lever mechanism to reduce 'liriction and to aid in operating naid mechanism, '1. have provided means jl'or conntenhalaneino the weight of the bed H and parts carried thereby. This means coinprieee a pair of coil eoni iireasion :qnringa 6R interpoeed between. the bane and bed (Fig: l), *ach spring being); in the pron ent. inetaneo conlincd at its upper end in a housing tit) fixed to the bed and coiled about and renting upon a stem Tl the lower end "2 ol which in threaded in the top ot the base and held in such position by a suitable loci; nut. These springs eonnt'er-balamre the \Ytlgllt oi the bed and its parts and will be put under additional compression when the bed is lowered so that the stored up pressure materially aids in elevating the bed on the upstroke. As a result of the use oi such counter-balancing means much weight is taken from the bearings of the lever mechanism and comparatively little force is required for operating such mechanism. Another advantage of this construction is that there is comparatively little wear on the parts employed for reciprocating the travelingband, and the motion is exceptionally smooth and free from vibration.

carried directly by the bed 14 at the back of the stretch of the traveling-band, paralleling the table 1 6, for backing the band for work onsaid table, as is well known in this art. By reciprocating the platen with the band instead of having the band reciprocate relative to the platen as was done heretofore I avoid the tearing of the band when work is pressed against the band toward the platen. No means is shown for supporting the table 16 in operative relation to the platen 7 3 as this forms no part of the present invention, it being manifest that any suitable or well known means may be employed for this purpose.

The circular work supporting table 17 emv braces one side of the roll 13 and two stretches of the traveling-band and is mounted in anovel manner for adjustment to different angular positions. This table is carried by a single post 74 supported for vertical adjustment in the end 75 of a knee bracket 76 fixed to the base 15. A key 77 (Fig. 10) operating in a key Way in the post 74: holds the latter against rotation. The

bracket end 75 is slotted lengthwise and adapted to be clamped onto the post 74 by means of a clamp screw 78 for locking said post in any adjusted position. By means of a hand-wheel nut 79 engaging the screw post and resting'on the top of the bracket end 75 said post and consequently the work table 17 may be raised and lowered as will be obvious. To the upper end of the post 74 is fixed a bracket 81 having a pair of dian'ietrically opposed arms 82 in a plane at right angles to the major axis of the machine and an intermediate arm 83 parallel with said axis. centric with the post 74 a socket 01' seat. 84.- for the reception of the spherical portion 85 of a table-supporting block 86. The table is attached to this block by bolts 87 passing through slots 88 (Fig. 9) in said block permitting adjustment of the table toward and from the roll 13 to accommodate rolls of different diameter. Each arm 82 is connected at its outerend to the table supporting block 86 by means of a bolt 89 the head of which is seated in a square socket 91 in the block and the threaded end of which passes loosely through its arm 82 and is equipped therebelow with a hand adjusting nut 92. It

will be manifest that by tightening and loosening the nuts 92 the work table 17 may This bracket also has con-' ridjustment of the table 17 on a horizontal axis at right angles :to said major axis is afforded by a connection between the arm- 83 and the table supporting block. In the present instance .this ad ustment is provided by means of a bolt 93 having a square head seated in a comp'lementa'l socket 9-1 in the It will be observed that a platen 73 isb'lock and passing loosely through the bracket arm 83 and equipped thereb'elow with a hand adjusting nut 95,-.and a screw sleeve 96 loose on the bolt 98, threaded .in the arm 83 as shown in Fig. 6 and "having a hand adjusting nut 9.7 which bears against a spherical =underface 98 on the block 86. By loosening the nut and turning the nut 97 the table 17 may be adjusted about the =t1 t11SV8l so axis in either direction, as will .be

obvious, and may be secured in such adjusted 1 position by tightening the nut 95. The construction just described provides for not only adjusting the work table 17 about a longitudinal and a transverse axis but also .universally .to any angular position within, of course, the limits of adjustment afforded by the particular construction.

It is believed that the foregoing conveys a clear understanding of the objects prefaced above and while I have illustratedbut a single working embodiment it should be understood that many changes might be made in details of construction and in the substitution of equivalents without departing from the spirit and scope of the present invention as expressed in the appended claims, in which I claim:

1. In a sander, a base, a traveling band of abrasive material, means supporting the same for vertical reciprocation relative to the base while traveling, means for vertically reciprocating said band support, a platen for backing up said band to assume the pressure of the work, and means supporting said platen for reciprocation vertically with said band, said platen support moving with said band support whereby the band merely travels across the front of said platen but does not reciprocate relative thereto in its vertical reciprocation substantially as and for the purposes described.

2. A sander comprising, in combination, 

